Heretofore, a semiconductor laser oscillator has been widely used for exciting a solid-state laser or a fiber laser, and higher luminance of the semiconductor laser oscillator has been achieved, whereby a processing machine of a direct diode laser (DDL) for use in direct processing has been widespread. As a DDL oscillator, it is an oscillator that uses a plurality of laser diodes, each of which has a high-output single emitter. This DDL oscillator emits lasers winch are individually locked to a plurality of wavelengths, and are subjected to spectrum beam coupling.